1. Field of the Invention
This invention relates to a process for the production of neutral-tasting pastes of alkyl ether sulfates in glycerol.
2. Statement of Related Art
In contrast to alkyl sulfates, alkyl ether sulfates have hardly ever been used in toothpastes on account of their unpleasant taste and aftertaste.
It is known from German patent application DE 30 44 481 that 1,4-dioxane can be removed from water-containing pastes of alkyl ether sulfates in admixture with water by azeotropic evaporation. DE-OS 34 47 867 describes a process for the removal of 1,4-dioxane from alkyl ether sulfates, in which an ethoxylated silicone oil is added to the water-containing surfactant paste for defoaming purposes and steam is subsequently passed through the resulting mixture. These processes give water-containing pastes of alkyl ether sulfates which, by virtue of their reduced 1,4-dioxane content and the lower danger potential resulting therefrom, may be used with advantage in detergents and cleaning preparations.
However, distillation-based operations involving water-containing alkyl ether sulfate pastes of relatively high concentration are complicated by the presence of gel phases. Accordingly, there is a need for processes which enable unwanted secondary products to be removed from alkyl ether sulfate pastes. These secondary products are only present in low concentrations and, as in the case of taste-forming or odor-emitting substances for example, are generally not known in their entirety.